In recent years, much attention has been paid to nanofibers, and they have been subjects of great interest in an aspect pertaining to cell culturing. In particular, fibers produced by electrospinning are fibers with a very small diameter, and they are advantageous in that they have a very large surface area per unit volume, are flexible, highly porous, and a large number of fibers are present per unit area, thus being capable of blending with other material(s) and exhibiting large distribution of an external stress. In a biomedical field, nanofiber aggregates (e.g. nanofiber mats) having a morphologically similar structure to the extracellular matrix of a human body are used as substrates for cell culturing, and mats that can be used by being placed in a cell culture dish (petri-dish) were commercialized and are being sold to serve a purpose of generally using nanofibers for cell culturing.
However, nanofiber mats are highly flexible, and thus handling thereof is not easy and there is much limitation to maintaining an evenly spread shape inside a dish. Therefore, they are initially fabricated into a form of an attachment to a cell culture dish or prepared with a very large thickness, and thus it is difficult to use them in various ways during an experiment, and they have various problems such as an increased cost and limited range of application.
In the meantime, barrier membranes used in guided bone regeneration (GBR) are materials that prevent a defective area of an osseous tissue from being exposed to a fibrous connective tissue, prevent bacteria from entering, and provide a site for bone regeneration. The barrier membranes are used in alveolar bone regeneration, the treatment of defects or the regeneration of other types of bones in various areas of a human body. Recently, the barrier membranes have been developed to perform additional functions as well as bone regeneration by containing additional bioactive factors. Depending on constituent materials, barrier membranes can be roughly categorized into inorganic barrier membranes, which consist of inorganic substances such as titanium, and polymer barrier membranes. The polymer barrier membranes can be categorized into being resorbable and non-resorbable, depending on whether they are absorbed in a human body or not.
Inorganic barrier membranes have advantages such as high rigidity and high structural stability, but they are highly incompatible with a human tissue. Non-resorbable polymer barrier membranes have relatively higher biocompatibility in comparison to inorganic barrier membranes and have relatively higher rigidity and structural stability in comparison to resorbable polymer barrier membranes. However, both inorganic barrier membranes and non-resorbable polymer barrier membranes have disadvantages in that they need to be kept continuously in a human body even after the recovery of defective tissues or require an additional surgery for the removal thereof.
In contrast, resorbable polymer barrier membranes are advantageous in that they have high biocompatibility, can perform a variety of functions such as shielding, drug-releasing, and the like, and do not require separate removal. Nevertheless, nanofiber-based resorbable polymer barrier membranes have a form of a nonwoven fabric by an electrospinning or freeze-drying process, and thus their rigidity value is very low. Resorbable polymer barrier membranes with low rigidity have limitations in that they are difficult to handle at a time of a procedure, enough space in a human body cannot be provided for the long term, and applying them to a heavily loaded part is challenging.